#### bluegoatwoods

##### New Member

So I'm picturing a 100 Watt panel in strong sunshine. The panel is outputting 100 Watts. So 100 Watts divided by 12 Volts would seem to indicate that this panel is delivering 8.3333 Amps to the battery. (My PWM controller is wasting perhaps 30% of that? Yeah. But at least I can account for this and beef up the system accordingly.)

So if I connected five panels in parallel this system ought to produce 8.3333 Amps times 5. For a total of 41 and a half Amps. Or something very close to that. I've forgotten the values I calculated to the right of the decimal.

If each panel had a 20 Watt controller, then I don't see that part of the system being particularly stressed. And those five controller outputs can be paralleled into one battery input, is that right? This would give me that .4c charge rate.

I suppose I'll go ahead and take controller loss into account. I'll add another panel (!) for that. So I've got six panels producing 8.33 Amps each for a total of (practically) 50 Amps. Nice! But multiplying 50 Amps by .7 estimated controller power loss gives me the disappointing total of a 35 Amp usable charge rate.

Wow! I might as well give it up right now. It was a fun thought experiment. But realistically it's not much more practical than a Lead Zeppelin.

I was going to ask if my reasoning was correct or had flaws. There's no point now. Though if there is some flaw and it really is more practical than I think it is, then I'd be glad to hear that.